ABB ACS150 series User Manual page 109

108
Parameters in the Long parameter mode
Index Name/Selection
3005 MOT THERM PROT
0 = NOT SEL
1 = FAULT
2 = ALARM
3006 MOT THERM TIME
256...9999 s
Actual signals and parameters
Description
Selects how the drive reacts when motor overtemperature is detected.
The drive calculates the temperature of the motor on the basis of the
following assumptions:
1) The motor is in the ambient temperature of 30 °C when power is applied to
the drive.
2) Motor temperature is calculated using either the user-adjustable (see
parameters 3006 MOT THERM TIME,
ZERO SPEED LOAD and
calculated motor thermal time constant and motor load curve. The load curve
should be adjusted in case the ambient temperature exceeds 30 °C.
Protection is inactive.
The drive trips on fault MOT OVERTEMP
temperature exceeds 110 °C, and the motor coasts to stop.
The drive generates alarm
temperature exceeds 90 °C.
Defines the thermal time constant for the motor thermal model, that is the
time within which the motor temperature has reached 63% of the nominal
temperature with steady load.
For thermal protection according to UL requirements for NEMA class motors,
use the rule of thumb: Motor thermal time = 35 · t6. t6 (in seconds) is
specified by the motor manufacturer as the time the motor can safely operate
at six times its rated current.
Thermal time for a Class 10 trip curve is 350 s, for a Class 20 trip curve
700 s, and for a Class 30 trip curve 1050 s.
Motor load
Temp. rise
100%
63%
Time constant
3007 MOT LOAD CURVE,
3009 BREAK POINT FREQ) or automatically
(code: F0009) when the
MOTOR TEMP (code: A2010) when the motor
Par. 3006
Def
1 = FAULT
3008
500 s
t
t